How to send an attachment from request to mail without first saving it to storage?

How to send an attachment from request to mail without first saving it to storage?

public function build(){
    $email = $this->from('mymail@gmail.com')
                        ->view('emails.contact');
     foreach(request()->file() as $file) {
                $email->attach($file->getRealPath(), [
                'as' => $file->getClientOriginalName(),
                'mime' => $file->getMimeType(),
        ]);
    }
}
return $email;

You can see it in the documentation https://laravel.com/docs/9.x/mail#attachments